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Mensuration | Exercise 10.1

Question 20

A piece of strings is 30 cm long. What will be the length of each side if the string is used to form:

(a) a square?

(b) an equilateral triangle?

(c) a regular hexagon?

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  • Solution

  • Transcript

Perimeter of square = 30 cm

4 × side = 30

Side = 30 / 4

Side = 7.5 cm

Perimeter of an equilateral triangle = 30 cm

3 × side = 30

Side = 30 / 3

Side = 10 cm

Perimeter of a regular hexagon = 30 cm

6 × side = 30

Side = 30 / 6

Side = 5 cm

"hello students welcome to leader learning question answer video solution my name is beljord kor and i'm your mathematics tutor so today's question is in the adjoining figure aob is a straight line ah this is a straight line now we have to find the value of x in the following angles so before solving the question guys one must know that you know since it's a straight line so all the angles okay angle a o c plus angle c o d plus angle d o b will together make up 180 degree all right guys so let's get started so three x minus seven plus 55 plus x plus 20 is equals to 180 degree now let's start solving it so 3x plus x will be 4x so let me write it as 4x now 55 plus 20 would be 75 and this is a minus 7 so let me write this minus 7 also so 75 minus 7 is how much let's see 7 8 9 10 11 12 13 14 15 8 and that would be 6. so 75 minus 7 is 68 which is equal to 180 now 4x is equals to 180 minus 68. so 4x would be 10 minus 8 is 2 and 7 minus 6 is 1 and 1 minus 0 is 1 or you can say x is equals to 4 times 2 is 8 9 10 11 and 4 times 7 4 times 6 is 24 4 times 7 is 28 and 4 times 8 is 32 so that means x is equals to 28 degrees your answer so but this is the answer of only x so let's put the value one by one so if i'm putting x over here so 28 times 3 is 3 times 8 is 24 and 3 times 2 is 6 7 8. so 84 minus 7 would be 7 8 9 10 11 12 13 14. 7 that would be 77 degree so i'm writing 77 degree over here this is 55 degree already and the other one is 28 plus 20 so that would be 48 degree so this would be 48 degree so for a check answer that if you will see that i have already discussed with you that if i want to check my answer so 77 plus 55 plus 48 are going to give you 180 degree solution only so that's the answer to your problem thank you so much student for watching the video if you have any doubt any questions any problem just drop down in the comment section that's all for today for more videos subscribe to lido thank you so much for watching and have a great day"

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Question 20

A piece of strings is 30 cm long. What will be the length of each side if the string is used to form:

(a) a square?

(b) an equilateral triangle?

(c) a regular hexagon?

  • Solution

  • Transcript

Perimeter of square = 30 cm

4 × side = 30

Side = 30 / 4

Side = 7.5 cm

Perimeter of an equilateral triangle = 30 cm

3 × side = 30

Side = 30 / 3

Side = 10 cm

Perimeter of a regular hexagon = 30 cm

6 × side = 30

Side = 30 / 6

Side = 5 cm

"hello students welcome to leader learning question answer video solution my name is beljord kor and i'm your mathematics tutor so today's question is in the adjoining figure aob is a straight line ah this is a straight line now we have to find the value of x in the following angles so before solving the question guys one must know that you know since it's a straight line so all the angles okay angle a o c plus angle c o d plus angle d o b will together make up 180 degree all right guys so let's get started so three x minus seven plus 55 plus x plus 20 is equals to 180 degree now let's start solving it so 3x plus x will be 4x so let me write it as 4x now 55 plus 20 would be 75 and this is a minus 7 so let me write this minus 7 also so 75 minus 7 is how much let's see 7 8 9 10 11 12 13 14 15 8 and that would be 6. so 75 minus 7 is 68 which is equal to 180 now 4x is equals to 180 minus 68. so 4x would be 10 minus 8 is 2 and 7 minus 6 is 1 and 1 minus 0 is 1 or you can say x is equals to 4 times 2 is 8 9 10 11 and 4 times 7 4 times 6 is 24 4 times 7 is 28 and 4 times 8 is 32 so that means x is equals to 28 degrees your answer so but this is the answer of only x so let's put the value one by one so if i'm putting x over here so 28 times 3 is 3 times 8 is 24 and 3 times 2 is 6 7 8. so 84 minus 7 would be 7 8 9 10 11 12 13 14. 7 that would be 77 degree so i'm writing 77 degree over here this is 55 degree already and the other one is 28 plus 20 so that would be 48 degree so this would be 48 degree so for a check answer that if you will see that i have already discussed with you that if i want to check my answer so 77 plus 55 plus 48 are going to give you 180 degree solution only so that's the answer to your problem thank you so much student for watching the video if you have any doubt any questions any problem just drop down in the comment section that's all for today for more videos subscribe to lido thank you so much for watching and have a great day"

Our top 5% students will be awarded a special scholarship to Lido.

subject-cta
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